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What is a covariant return type?
...ference to a MyFoo object will be able to invoke clone() and know (without casting) that the return value is an instance of MyFoo. Without covariant return types, the overridden method in MyFoo would have to be declared to return Object - and so calling code would have to explicitly downcast the re...
How to alter a column's data type in a PostgreSQL table?
... For some other cases, you might need to specify the way to cast like ALTER TABLE tbl_name ALTER COLUMN col_name TYPE integer USING col_name::integer;
– Nobu
May 1 '14 at 17:45
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Convert interface{} to int
I'm trying to get a value from a JSON and cast it to int but it doesn't work, and I don't know how to do it properly.
10 An...
C# : 'is' keyword and checking for Not
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Update (considering the OP's code snippet):
Since you're actually casting the value afterward, you could just use as instead:
public void Update(DocumentPart part) {
part.Update();
IContainer containerPart = part as IContainer;
if(containerPart == null) return;
foreach(Docu...
Do interfaces inherit from Object class in java
...bject will also accept a reference of any interface type. Moreover you can cast interface to an Object implicitly without any compiler error.
– nme
Feb 10 '19 at 14:03
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Is there a Boolean data type in Microsoft SQL Server like there is in MySQL? [duplicate]
...valuates to (or converts to in some cases) a 1.
declare @i int = -42
print cast(@i as bit) --will print 1, because @i is not 0
Note that SQL Server uses three valued logic (true, false, and NULL), since NULL is a possible value of the bit data type. Here are the relevant truth tables -
More in...
How different is Objective-C from C++? [closed]
...Objective-C is a more perfect superset of C. In C and Objective-C implicit casting from void* to a struct pointer is allowed.
Foo* bar = malloc(sizeof(Foo));
C++ will not compile unless the void pointer is explicitly cast:
Foo* bar = (Foo*)malloc(sizeof(Foo));
The relevance of this to every da...
Fast ceiling of an integer division in C / C++
...promote the arguments into long long's? And doesn't that cost anything, up-casting or down-casting?
– einpoklum
Feb 13 '16 at 20:51
1
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Make copy of an array
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The cast is unnecessary; a good static analyzer will warn about it. But cloning is definitely the best way to make a new copy of an array.
– erickson
Apr 26 '11 at 4:23
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Can an int be null in Java?
...be checked for null, however, you can safely assign null to int in Java by casting it to Integer, for example if the check(root) method can return null then you can safely cast it to int by doing something like this: int data = (Integer)check(node);
– sactiw
O...